The ability of insulin to suppress whole body and regional lipolysis will be evaluated in lean (n=8), lower-body obese (n=8), and upper-body obese (n=8) women. Whole body lipolysis will be evaluated by 2H5-glycerol kinetics and regional lipolysis will be evaluated by placing microdialysis probes in sub-cutaneous abdominal and femoral adipose tissue. Relative changes in glycerol during insulin infusion will be used to assess inhibition of lipolysis. Intra-abdominal fat mass will be assessed by CT.